quantumdude
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Originally posted by wuliheron
For me, it is THE point. Whether you view it as an argument or statement of fact depends upon your point of view. Of course if you take the point of view it is a simple statement of fact it supports classical logic, but then it becomes a tautological argument.
A few points:
First, no matter how you look at it, logical constructions of the form If p then q. are statements and not arguments. An argument--by definition--has at least two statements.
Second, I don't think that there is any such thing as a "tautological argument". Tautologies are types of statements, not arguments.
Third, statements of the form If p then q. are not tautological unless p=q, which is not true in this case.
Again, you are using dialectical logic to assert the validity of dialectical logic. You are saying that truth is not falsehood and then attempting to use this fundamental assumption to prove that truth must lead to truth using these rules and falsehood must lead to falsehood.
No, I am not proving anything. I am defining[/color] deductive validity. Also, I am not saying anything about the definition of "truth" or "falsehood".
Ahkron has it right with his analogy, and I go into it further with my 'computer program' explanation. The definition of deductive validity is completely independent of the definition of truth.
As Kurt Godel proved, any system must be based at least in part on axioms that can only be taken on faith. Hence even logical systems are ultimately based on faith as much as anything else and the roots of this faith can be traced in the west to the pervasive use of reductio ad absurdum in ancient Greece.
I understand the implications of Incompleteness, but they have no bearing on the definition of deductive validity, unless you want to prove that logic is "right", which is not what I am doing here.
The rest of your post deals with the question, "How can I know which logic is correct?" which is not what I am getting at here. I was dividing logic into two categories (in response to FZ's question), basically to show that logic cannot be used to get to any "absolute truths" about reality, and as you point out, about itself, either.
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